Biodiversity, Extinction, and the End of Evolution

Nat­ur­al selec­tion derives its power to trans­form from the sur­viv­al of some and the demise of oth­ers, and from dif­fer­en­tial repro­duct­ive suc­cess. But we nurse our sick back to health, and mat­ing is no longer a priv­ilege that males beat each oth­er sense­less to secure. As a res­ult, even the less fit get to pass on their genes. Promis­cu­ity and sperm com­pet­i­tion have giv­en way to spir­itu­al love; the fit­test and the unfit are treated as equals, and equally flour­ish. With the advent of cul­ture and our fine sens­ib­il­it­ies, the assump­tion was, nat­ur­al selec­tion went by the board. [How­ever,] research­ers have dis­covered in our DNA evid­ence that cul­ture, far from halt­ing evol­u­tion, appears to accel­er­ate it.

The first response most eco­lo­gists give when asked about diversity gradi­ents tends to emphas­ize the com­plex­ity of inter­act­ing pres­sures on diversity. But when pressed, many eco­lo­gists will admit they believe in one or at most two main causes of diversity gradi­ents and that we are get­ting closer to a con­sensus as to what those are. The trouble is, there is no agree­ment among those who fore­see con­sensus as to what the con­sensus will be.

[The glob­al epi­dem­ic of same­ness] has no pre­cise para­met­ers, but wherever its shad­ow falls, it leaves the land­scape mono­chro­mat­ic, mono­cul­tur­al, and homo­gen­eous. Even before we’ve been able to take stock of the enorm­ous diversity that today existsâ€‰â€”â€‰from undes­cribed microbes to undoc­u­mented tonguesâ€‰â€”â€‰this epi­dem­ic car­ries away an entire human lan­guage every two weeks, des­troys a domest­ic­ated food-crop vari­ety every six hours, and kills off an entire spe­cies every few minutes. The fal­lout isn’t merely an assault to our aes­thet­ic or even eth­ic­al val­ues: As cul­tures and lan­guages van­ish, along with them go vast and ancient store­houses of accu­mu­lated know­ledge. And as spe­cies dis­ap­pear, along with them go not just valu­able genet­ic resources, but crit­ic­al links in com­plex eco­lo­gic­al webs.